<!--
  Any copyright is dedicated to the Public Domain.
  http://creativecommons.org/publicdomain/zero/1.0/
-->
<!DOCTYPE HTML>
<html>
  <head>
    <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js">
    </script>
    <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
  </head>
  <body>
    <script type="text/javascript">
      SimpleTest.waitForExplicitFinish();

      const enabledPref = "dom.workers.enabled";

      is(SpecialPowers.getBoolPref(enabledPref), true,
         "Workers should be enabled.");

      SpecialPowers.pushPrefEnv({"set": [[enabledPref, false]]}, test1);

      function test1() {
        ok(!("Worker" in window), "Worker constructor should not be available.");

        var exception;
        try {
          var worker = new Worker("workersDisabled_worker.js");
        }
        catch(e) {
          exception = e;
        }

        ok(exception, "Shouldn't be able to make a worker.");

        SpecialPowers.pushPrefEnv({"set": [[enabledPref, true]]}, test2);
      }

      function test2() {
        ok(("Worker" in window), "Worker constructor should be available.");

        const message = "Hi";

        var worker = new Worker("workersDisabled_worker.js");
        worker.onmessage = function(event) {
          is(event.data, message, "Good message.");
          SimpleTest.finish();
        }
        worker.postMessage(message);
      }
    </script>
  </body>
</html>

